16. PR -- Priority The scheduling priority of the task. If you see `rt' in this field, it means the task is running under real time scheduling priority. Under linux, real time priority is somewhat misleading since traditionally the operating itself was not preemptible. And while the 2.6 kernel can be made mostly preemptible, it is not always so.
I attempted to change a running process to have realtime priority:
$ sudo chrt -f -p 1 2179 $ chrt -m SCHED_OTHER min/max priority : 0/0 SCHED_FIFO min/max priority : 1/99 SCHED_RR min/max priority : 1/99 SCHED_BATCH min/max priority : 0/0 SCHED_IDLE min/max priority : 0/0 SCHED_DEADLINE min/max priority : 0/0 $ chrt -p 2179 pid 2179's current scheduling policy: SCHED_FIFO pid 2179's current scheduling priority: 1 $
Tasks: 255 total, 3 running, 252 sleeping, 0 stopped, 0 zombie %Cpu(s): 4.4 us, 0.3 sy, 0.0 ni, 95.3 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0 st KiB Mem : 19658969+total, 19371019+free, 2405528 used, 473984 buff/cache KiB Swap: 4194300 total, 4194300 free, 0 used. 19352804+avail Mem PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 2179 myuser -2 0 25552 2892 2648 R 100.0 0.0 67:16.22 my_application
It shows -2 as priority. Should it be
I do see some process like
rt as the priority tho.